Home / 1,221.15-1,831.86-399.45

Finding the Fourth Proportional to 1,221.15, 1,831.86 and 399.45

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Solution

The fourth proportional to 1,221.15, 1,831.86 and 399.45 is: 599.22

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,221.15 : 1,831.86 = 399.45 : x
  2. Step 2: Convert to fraction form
    1,221.15/1,831.86 = 399.45/x
  3. Step 3: Cross multiply
    1,221.15x = 1,831.86 × 399.45
  4. Step 4: Simplify right side
    1,221.15x = 731,736.48
  5. Step 5: Solve for x
    x = 731,736.48/1,221.15
  6. Step 6: Final answer
    x = 599.22

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.